1. Field of the Invention
The present invention relates generally to an automotive air conditioner system which can automatically control temperature of discharge air to be discharged into a vehicular cabin, the amount of the discharge air, mode of discharge of the discharge air into the vehicular cabin. More particularly, the invention relates to an automatic automotive air conditioner system which has improved transition characteristics in varying temperature of the discharge air.
2. Description of the Background Art
Various automotive air conditioner systems which automatically adjust discharge air temperature, have been proposed and put into the market. One of the typical automatic automotive air conditioner systems has been disclosed in the Japanese Patent First (unexamined) Publication (Tokkai) Showa 60-61319.
Such prior proposed automatic automotive air conditioner systems monitors environmental conditions affecting air discharge in the vehicular cabin. In the aforementioned Patent, there has been proposed an automatic control of a temperature of the discharge air to be discharged into the vehicular cabin according to environmental conditions represented by preselected control parameters, such as an ambient air, insolation, desired room temperature which may be set by an occupant of the vehicular cabin, and so forth.
In general, in such prior proposed automatic air conditioner systems, the temperature of the discharge air is derived on the basis of the preselected control parameters, such as ambient air temperature, insolation value, room temperature and desired room temperature. When the environmental condition is as different from the desired vehicular cabin condition, too cool or too hot discharge air tends to be discharged to cause discomfort on the passengers in the vehicular cabin. In addition, when environmental condition is suddenly changed, discharge air temperature to be discharged into the vehicular cabin suddenly changes to bring discomfort for the passenger. In one typical case, when insolation value suddenly increases, the insolation value representative control parameter changes suddenly to change the discharge air temperature to be derived based thereon. When sunbeam starts to irradiate on an insolation sensor, the discharge air temperature tends to be lowered suddenly and discharged toward the passenger. Such a sudden change makes the passenger surprised and results in an uncomfortable feeling as a result of the sudden change of the discharge air temperature which compensates the sudden change in heat value in the vehicular cabin due to the sunshine so as to maintain the desired temperature condition in the vehicular cabin.